BACKGROUND: Treatment of visceral leishmaniasis (VL) is far from satisfactory. There is an urgent need for a therapy that is efficacious, safe, affordable, and of short duration. METHODS: A randomized open-label study was conducted to assess the efficacy and safety of 2 regimens of paromomycin administered intramuscularly. Group A received 11 mg/kg/day for 14 days (n = 217) and group B received 11 mg/kg/day for 21 days (n = 112) for the treatment of VL in India. RESULTS: Mild grade injection site pain was the most common adverse event. There was no nephrotoxicity, but 4 patients in group A had to discontinue treatment because of grade 3 elevation of hepatic enzymes. Initial cure was observed in 91.2% and 96.4% of patients in group A and group B, respectively. Definitive cure at 6 months of follow up was seen in 82% of patients in group A and 92% of patients in group B by intention-to-treat analysis and in 84.3% of patients in group A and 92.8% of patients in group B by per protocol analysis. CONCLUSIONS: Although the cure rate in the group of patients who received the 14-day regimen was not optimal, the results with respect to initial cure were encouraging. Further studies that combine a short course of paromomycin with treatment with another antileishmanial agent are warranted. ( ClinicalTrials.gov identifier: NCT00629031).